If you’re sending bulk SMS in India, understanding DLT template categories isn’t optional—it’s mandatory. The Telecom Regulatory Authority of India (TRAI) requires every commercial SMS to use a registered template, and choosing the wrong category can result in message blocking, penalties, or even header suspension.
In this comprehensive guide, we’ll break down the four DLT template categories, explain when to use each one, and provide real-world examples to help you stay compliant while maximizing message delivery.
What Are DLT Template Categories?
Under TRAI’s TCCCPR 2018 regulations, all commercial SMS must be registered on the Distributed Ledger Technology (DLT) platform. Each message template falls into one of four categories, each with specific rules, use cases, and sender ID requirements.
Getting this right is crucial because:
- Wrong categorization = Blocked messages
- Compliance violations = Financial penalties
- Incorrect sender IDs = Template rejection
Let’s dive into each category.
1. Transactional Templates: Banking OTPs Only 🏦
What Qualifies as Transactional?
Transactional templates have the most restrictive definition in India’s DLT framework. Despite what the name suggests, this category is exclusively for banking OTPs—not all transaction-related messages.
Key Criteria:
- ✅ Contains One Time Password (OTP)
- ✅ Required to complete a banking transaction
- ✅ Initiated by the bank customer
- ✅ Only for banks, NBFCs, and RBI-approved digital wallets
Sender ID Requirements:
- Must use: Alphanumeric sender IDs (e.g., SBIBNK, HDFCBK)
- Cannot use: Numeric sender IDs
Variable Limit:
- 4-5 variables allowed (though new TRAI direction suggests limiting to 2-3)
Real-World Examples:
✅ CORRECT Transactional Template:
Dear Customer, {#var#} is your OTP for completing net banking transaction of Rs.{#var#}. Valid for 10 minutes. Do not share. – AXISBK
✅ CORRECT Transactional Template:
Your OTP for UPI payment of Rs.{#var#} to {#var#} is {#var#}. Valid for 5 mins. Never share this OTP. – PAYTMBK
❌ WRONG – This is NOT Transactional:
Your Flipkart order OTP is {#var#}. Use this to receive your delivery.
Why? This is e-commerce, not banking. Should be Service Implicit.
Common Mistakes:
- Using transactional category for e-commerce OTPs (these are Service Implicit)
- Including promotional content with banking OTPs
- Using for authentication OTPs on websites (these are Service Implicit)
2. Service Implicit Templates: The Workhorse Category 📬
What Qualifies as Service Implicit?
This is the most commonly used category for legitimate business communications. Service Implicit messages arise from a customer’s existing relationship with your business and are in their interest to receive.
Key Criteria:
- ✅ Arises from customer action or existing relationship
- ✅ Not promotional in nature
- ✅ Customer benefits from receiving it
- ✅ Examples: Order updates, appointment reminders, delivery alerts, bill notifications
Sender ID Requirements:
- Must use: Alphanumeric sender IDs (e.g., AMAZON, SWIGGY, AIRTEL)
- Cannot use: Numeric sender IDs
Variable Limit:
- 4-5 variables allowed (2-3 recommended per new guidelines)
Real-World Examples:
✅ E-commerce Order Confirmation:
Your order #{#var#} has been confirmed. Expected delivery by {#var#}. Track at www.yourstore.com/track – SHOPIFY
✅ Food Delivery Update:
Your order from {#var#} is out for delivery. Your delivery partner {#var#} will reach you in {#var#} minutes. – ZOMATO
✅ Appointment Reminder:
Reminder: Your appointment with Dr.{#var#} is scheduled on {#var#} at {#var#}. Clinic address: {#var#}. – MYHSPTAL
✅ Bill Payment Alert:
Dear {#var#}, your electricity bill of Rs.{#var#} is due on {#var#}. Pay now to avoid late charges. – BESCOM
✅ Booking Confirmation:
Your hotel booking #{#var#} at {#var#} for {#var#} nights is confirmed. Check-in: {#var#}. – GOIBIBO
When to Use Service Implicit:
- Order confirmations and shipping updates
- Appointment bookings and reminders
- Password resets and login OTPs (non-banking)
- Bill payment reminders
- Subscription renewals (without promotional offers)
- Delivery notifications
- Account balance alerts (non-banking)
Common Mistakes:
- Adding discount offers (makes it Service Explicit)
- Using for pure marketing messages
- Sending to customers with no existing relationship
3. Service Explicit Templates: Consent Required ✉️
What Qualifies as Service Explicit?
Service Explicit is the middle ground between service messages and promotional content. These messages may contain offers or promotions but are sent to existing customers who have explicitly consented.
Key Criteria:
- ✅ Requires explicit digitally-verified consent
- ✅ May contain promotional elements or offers
- ✅ Sent only to opted-in customers
- ✅ Examples: Upgrade offers, renewal with discounts, personalized deals
Sender ID Requirements:
- Must use: Alphanumeric sender IDs (e.g., HDFC, AIRTEL)
- Cannot use: Numeric sender IDs
Variable Limit:
- 4-5 variables allowed (2-3 recommended)
Consent Requirement:
Must link a Consent Template ID when registering. This proves customers opted in to receive such messages.
Real-World Examples:
✅ Pre-approved Loan Offer:
Dear {#var#}, you are eligible for a pre-approved personal loan of Rs.{#var#} at {#var#}% interest. Apply now at www.bank.com/loan – HDFCBK
✅ Subscription Renewal with Discount:
Hi {#var#}, your Netflix subscription expires on {#var#}. Renew now and get {#var#}% off for 3 months. Visit app.netflix.com – NETFLIX
✅ Exclusive Customer Offer:
Exclusive for you! Upgrade to {#var#} plan and save Rs.{#var#}/month. Offer valid till {#var#}. Call 1800-XXX-XXXX – AIRTEL
✅ Credit Card Upgrade:
Dear {#var#}, upgrade to our Platinum Card and enjoy {#var#} reward points. Zero joining fee till {#var#}. Apply: www.bank.com – ICICIBC
Service Explicit vs Service Implicit: The Key Difference
| Aspect | Service Implicit | Service Explicit |
| Consent | Implied by relationship | Explicit opt-in required |
| Content | Pure information | May include offers |
| Consent Template | Not required | Mandatory |
| Example | “Your order shipped” | “Your order shipped + 20% off next purchase” |
Common Mistakes:
- Sending to customers without proper consent records
- Using without linking Consent Template ID
- Mixing pure service information (use Service Implicit instead)
4. Promotional Templates: Pure Marketing Messages 📢
What Qualifies as Promotional?
Promotional templates are for pure marketing communications—sales, offers, promotions, and advertising messages sent to acquire or retain customers.
Key Criteria:
- ✅ Marketing and advertising content
- ✅ Sent to promote products, services, or events
- ✅ Can be sent to prospects (not just existing customers)
- ✅ Subject to DND (Do Not Disturb) regulations
Sender ID Requirements:
- Must use: 6-digit numeric sender IDs ONLY (e.g., 567890, 123456)
- Cannot use: Alphanumeric sender IDs (Critical rule!)
Variable Limit:
- Only 2-3 variables allowed (stricter than other categories)
- Third variable requires justification
DND Compliance:
Messages will NOT be delivered to numbers registered on DND list, even with proper templates.
Real-World Examples:
✅ Sale Announcement:
Mega Diwali Sale! Get up to {#var#}% OFF on all electronics. Valid till {#var#}. Shop now at www.store.com – 567890
✅ New Product Launch:
Introducing the new {#var#}! Pre-order now and get {#var#}% cashback. Limited period offer. Visit www.brand.com – 123456
✅ Event Invitation:
You’re invited to our Annual Fashion Show on {#var#} at {#var#}. Register free at www.event.com. Limited seats! – 789012
✅ Restaurant Promotion:
Weekend Special at {#var#}! Get {#var#}% off on all orders above Rs.500. Order now via app or call 1800-XXX-XXXX – 456789
When to Use Promotional:
- Sales and discount announcements
- New product launches
- Event promotions
- Store opening notifications
- Contest and giveaway announcements
- Cold outreach to prospects
- Brand awareness campaigns
Common Mistakes to Avoid:
- ❌ Using alphanumeric sender ID for promotional content (instant rejection!)
- ❌ Using more than 3 variables
- ❌ Sending to DND numbers (automatic blocking)
- ❌ Disguising promotional content as service messages
Quick Decision Matrix: Which Category Should I Use?
Use this flowchart to choose the right category:
Is it a banking OTP?
├─ YES → Transactional
└─ NO → Continue…
Does it contain any promotional offer/discount?
├─ YES → Is customer existing and consented?
│ ├─ YES → Service Explicit
│ └─ NO → Promotional
└─ NO → Continue…
Does customer have existing relationship with you?
├─ YES → Is it order/appointment/bill related?
│ ├─ YES → Service Implicit
│ └─ NO → Re-evaluate if truly necessary
└─ NO → Promotional
Sender ID Requirements: The Critical Rule
| Template Category | Allowed Sender ID Type | Example |
| Transactional | Alphanumeric only | SBIBNK, HDFCBK |
| Service Implicit | Alphanumeric only | AMAZON, SWIGGY |
| Service Explicit | Alphanumeric only | AIRTEL, NETFLIX |
| Promotional | Numeric only (6 digits) | 567890, 123456 |
⚠️ Critical Warning: Using an alphanumeric sender ID for promotional messages is the #1 reason for template rejection. This rule is strictly enforced.
Variable Usage: The New Guidelines
As per TRAI’s February 2023 direction:
Maximum Variables by Category:
- Transactional: 4-5 variables (special banking exemption)
- Service Implicit: 4-5 variables (but 2-3 recommended)
- Service Explicit: 4-5 variables (but 2-3 recommended)
- Promotional: 2-3 variables maximum (strictly enforced)
Variable Rules:
✅ Use format: {#var#} only
✅ Each variable can hold up to 30 characters
✅ Must be separated by actual text (not just spaces or commas)
✅ Cannot have consecutive variables: ❌ {#var#} {#var#} or {#var#},{#var#}
Real-World Multi-Category Examples by Industry
E-commerce Business:
Service Implicit (Order Update):
Your order #{#var#} has been dispatched. Track at www.store.com/track-{#var#} – MYSTORE
Service Explicit (Renewal Offer):
Hi {#var#}, renew your Prime membership by {#var#} and get {#var#} months extra free! – MYSTORE
Promotional (Sale Campaign):
Flash Sale! Get {#var#}% off on fashion. Today only! Shop: www.store.com/sale – 567890
Healthcare Provider:
Service Implicit (Appointment):
Your appointment with Dr.{#var#} is confirmed for {#var#} at {#var#}. Clinic: {#var#} – MEDICARE
Service Explicit (Health Package):
Dear {#var#}, get our Annual Health Checkup at {#var#}% discount. Package includes {#var#} tests. Book now – MEDICARE
Promotional (New Service):
Introducing Home Sample Collection! Book health tests from home. Call {#var#} or visit www.lab.com – 789012
Banking/Financial:
Transactional (OTP):
{#var#} is your OTP for net banking transaction of Rs.{#var#}. Valid for 10 mins. Do not share – AXISBK
Service Implicit (Balance Alert):
Your savings account {#var#} has been credited with Rs.{#var#} on {#var#}. Available balance: Rs.{#var#} – AXISBK
Service Explicit (Loan Offer):
Dear {#var#}, you are pre-qualified for a personal loan of Rs.{#var#} at {#var#}% interest. Apply: www.bank.com – AXISBK
Common Template Rejection Reasons by Category
Transactional Rejections:
- ❌ Non-banking OTP marked as transactional
- ❌ Mixed promotional content with banking OTP
- ❌ Used by non-banking entities
Service Implicit Rejections:
- ❌ Contains discount offers (should be Service Explicit)
- ❌ Sent to customers with no relationship
- ❌ Purely promotional in nature
Service Explicit Rejections:
- ❌ No Consent Template ID linked
- ❌ Using numeric sender ID instead of alphanumeric
- ❌ Missing consent records
Promotional Rejections:
- ❌ Using alphanumeric sender ID (must be numeric!)
- ❌ More than 3 variables
- ❌ Category mismatch with header type
Best Practices for Template Registration
1. Choose Category Based on Content, Not Preference
Don’t try to game the system by marking promotional content as service messages. Operators scrutinize content during approval.
2. Match Header Type to Category
- Transactional, Service Implicit, Service Explicit = Alphanumeric
- Promotional = Numeric (6 digits)
3. Keep Organization Name Visible
Every template must clearly show your brand/company name for transparency.
4. Minimize Variables
Stick to 2-3 variables even if more are allowed. Keeps templates versatile and approval faster.
5. Separate Templates for Different Purposes
Don’t try to create one “master template” for multiple scenarios. Create specific templates for specific use cases.
6. Plan for Regional Languages
Each language needs a separate template. Plan accordingly if you operate in multiple states.
7. Test Before Bulk Deployment
Send test messages to ensure template works correctly before launching campaigns.
Template Approval Timeline
| Step | Timeline | Action Required |
| Template Submission | Day 0 | Submit via DLT platform |
| Operator Review | 1-2 working days | Wait for approval |
| Approval/Rejection | Day 2 | Check status |
| Corrections (if rejected) | 1 day | Fix and resubmit |
| Final Approval | Day 3-4 | Ready to use |
Pro Tip: Submit templates well before campaign launch dates to account for potential rejections and resubmissions.
Managing Your Template Portfolio
Regular Maintenance Required:
✅ Quarterly Re-verification: TRAI now mandates periodic verification
✅ 30-Day Activity Rule: Unused templates may be deactivated
✅ Consent Record Updates: Keep consent database current
✅ Template Audits: Review and remove obsolete templates
Portfolio Organization Tips:
- Name templates descriptively (e.g., “Order-Confirmation-v1”, “Sale-Announcement-Diwali”)
- Maintain a spreadsheet of Template IDs with use cases
- Document which templates are active vs. archived
- Track approval/rejection reasons for learning
Frequently Asked Questions
Can I use the same template across multiple telecom operators?
Yes! Templates registered with one operator are valid across all operators. No need to re-register for each operator.
What happens if I send a promotional message using an alphanumeric sender ID?
The message will be rejected immediately, and repeated violations can lead to header suspension or disconnection.
Can I edit a template after approval?
No. You must register a new template with the changes, get it approved, and then start using the new Template ID.
Do I need separate templates for SMS in different languages?
Yes, each language requires separate template registration in the native script (Hindi, Tamil, Telugu, etc.).
How do I link multiple headers to one template?
Within the same category, you can link multiple headers to a single template through the DLT platform during registration.
Penalties for Non-Compliance
Understanding the risks helps prioritize compliance:
Immediate Consequences:
- 🚫 Message delivery failures (100% blocking)
- 🚫 Template rejection and delays
- 🚫 Wasted SMS credits
Escalated Penalties:
- ⚠️ Sender ID suspension (temporary)
- ⚠️ Header disconnection (permanent)
- ⚠️ Entity blacklisting
- ⚠️ Financial penalties from TRAI
- ⚠️ Legal action for repeated violations
Conclusion: Get Your Category Right the First Time
Choosing the correct DLT template category isn’t just about compliance—it’s about ensuring your messages reach customers when they need them most. Here’s your action plan:
- Audit your current SMS types and categorize them correctly
- Register separate templates for each use case and category
- Match sender ID types to template categories (alphanumeric vs. numeric)
- Implement consent management for Service Explicit and Promotional messages
- Test thoroughly before launching bulk campaigns
- Monitor performance and maintain your template portfolio
Remember: When in doubt, err on the side of caution and choose a more restrictive category. It’s better to use Service Explicit instead of Service Implicit if there’s any promotional content, and always use Promotional for pure marketing messages.
Need Help with DLT Template Registration?
Understanding template categories is just the first step. For a complete guide on the registration process, validation rules, and common pitfalls, check out our comprehensive DLT Template ID Registration Guide.
Ready to start sending compliant bulk SMS? TechTo Networks offers complete DLT registration support, template consultation, and enterprise messaging solutions. Contact us for expert guidance.